In a manufacturing process of a semiconductor device or a liquid crystal display, a plasma processing apparatus such as a plasma etching apparatus, a plasma CVD film forming apparatus or the like is used to perform a plasma process such as an etching process, a film forming process or the like on a target substrate to be processed such as a semiconductor wafer, a glass substrate or the like.
Recently, as for the plasma processing apparatus, some attention has been paid to a RLSA (Radial Line Slot Antenna) microwave plasma processing apparatus capable of uniformly generating a surface wave plasma in a high density and at a low electron temperature (see, e.g., Japanese Patent Application Publication No. 2007-109457).
The RLSA microwave plasma processing apparatus includes a planar antenna (a radial line slot antenna) provided at an upper portion of a chamber, the planar antenna having slots formed in a predetermined pattern. A microwave generated from a microwave generator passes through a coaxial waveguide and is radiated into a chamber through the slots of the planar antenna. By a thus-produced microwave electric field, a gas introduced into the chamber is turned into a plasma and, thus, a target object, e.g., a semiconductor wafer, is processed by the plasma.
Further, there is suggested a plasma processing apparatus having a microwave plasma source for dividing a microwave into a plurality of microwaves, amplifying the microwaves by a solid state amplifier, transmitting the microwaves to the chamber through a plurality of antenna modules, each of which including a planar antenna having slots as in the case of the coaxial waveguide, and spatially combining the microwaves in the chamber (International Patent Application Publication No. 2008/013112 pamphlet (WO2008/013112A).
In order to supply an electromagnetic wave power, e.g., a microwave power, to the coaxial waveguide, a power supply port is generally provided in an extension of the coaxial waveguide, and the power is supplied therefrom, as described in WO2008/013112A.
However, due to the design of the apparatus, a driving mechanism or another member may be disposed at the portion corresponding to the extension of the coaxial waveguide. In that case, it is not possible to effectively supply the power.